Coordination-assisted synthesis of iron-incorporated cobalt oxide nanoplates for enhanced oxygen evolution

Oxygen evolution reaction (OER) plays a vital role in green technologies including water splitting and carbon dioxide reduction. As promising alternatives of noble metals–based OER electrocatalysts such as IrO₂ and RuO₂, the OER performance of nanostructured Co-based materials is far from satisfactory. In this report, a coordination-assisted etching strategy is proposed to incorporate iron into cobalt oxide porous nanoplates, producing composite nanostructures with optimized Co:Fe ratio that manifest significantly enhanced OER performance (an overpotential of 304 mV at 10 mA/cm² as well as a low Tafel slope of 38 mV/dec). The enhancement can be attributed to the modulated electronic structure of cobalt, favorable absorption energy of OER intermediates, and the formation of more oxygen vacancies. This work highlights the importance of rational integration of iron with cobalt for optimal electrocatalytic performance enabled by the coordination-assisted etching strategy, providing more opportunities for the design and synthesis of mixed metal electrocatalysts for energy conversion and storage.